There's a mixture of Na2CO3 and NaHCO3. Two samples of 25cm3 of this mixture is titrated using 0.1 Moldm-3 HCl with phenothaline and methyl orange. 10cm3 and 30cm3 of HCl was used respectively. 25cm3 from the sample was reacted using Ba(OH)2. WEhats the mass of the precipitation ?

Stage in which a typical star has completely stopped fusion

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

Which process transfers heat from inside earth to its surface? convection currents in mantle pulling away of tectonic plates drawing in of tectonic plates convection currents in crust